Computing devices, such as notebook computers, personal digital assistants, mobile communication devices, portable entertainment devices (e.g., handheld video game devices, multimedia players) may include user interface devices that facilitate interaction between a user and the computing device.
One type of user interface device that has become more common operates by way of capacitance sensing. A capacitance sensing system may include a touch screen, touch-sensor pad, a touch-sensor slider, or touch-sensor buttons, and may include an array of one or more capacitive sensor elements (also referred to as sensor electrodes). Capacitive sensing typically involves measuring, through sensor signals (e.g., increases or decreases in electrode responses), a change in capacitance associated with the capacitive sensor elements to determine a presence of a conductive object (e.g., a user's finger or head) relative to the capacitive sensor elements. However, a user's finger or head is difficult to detect and process when water (e.g., water droplets) contacts and settles on the touch screen. Therefore, a need exists for effective capacitance sensing when water is on the touch screen.